what deserves reverence in us is that which approaches most nearly to
the moral law in character. The appetites, the affections, the passions,
have each their own separate objects. They may be useful in the highest
degree, but they cannot in themselves deserve reverence, for their
objects are not the moral law; they must therefore be absolutely
subordinated to the will and the conscience which have for their
objects the very law itself. Holiness consists in the subjection of the
whole being, not in act alone, but in feeling and desire as well, to the
authority of conscience.

If we are thinking of other moral agents, duty prescribes strict and
unfailing justice; and justice in its highest and purest form is love,
the unfailing recognition of the fullest claims that can be made on us
by all who share our own divine superiority: to love God above all else,
and to love all spiritual beings as we love ourselves, this is duty in
relation to other spiritual beings.

If we are thinking of creatures which, whether moral agents or not, are
capable of pain and pleasure, our duty takes the form of goodness or
tenderness. We have no right to inflict pain or even refuse pleasure
unless, if the circumstances were reversed, we should be bound in
conscience to be ready in our turn to bear the same infliction or
refusal. The precept, Do as you would be done by, is here supreme, and
it is to this class of duties that that precept applies, and the limits
of our right to inflict pain on other creatures, whether rational or
irrational, will be determined by this rule.

And, lower still, our duty to things that are incapable of all feeling
is summed up in that knowledge of them and that use of them which makes
them the fittest instruments of a moral life.